Department of Civil and Environmental Engineering, Western Ontario University, London, ON, N6A 5B9, Canada,
Environ Sci Pollut Res Int. 2014 Sep;21(17):10096-107. doi: 10.1007/s11356-014-2892-x. Epub 2014 Apr 27.
In this study, recycled Ni smelter slag has been used as a reactive medium for arsenic (As) removal from aqueous solutions. The results of the study showed that 10.16-11.43-cm long columns containing 451-550 g of slag operated for at least 65 days were able to remove 99-100 % As species from continuously flowing contaminated water at an initial As concentration of 10 mg/L. The removal capacities were found to be 1.039 to 1.054 mg As per g of slag. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy data also showed that electrostatic attraction and oxidation-reduction reactions between As species and mixed iron oxides present in the slag were the main mechanisms for the removal of arsenic from aqueous solutions. Theoretical multiplet analysis of XPS data revealed that the amount of goethite in the slag increased from 22 to 60 % during arsenic removal by adsorption and the percentage of magnetite decreased from 50 to 40 %. These changes indicate that redox-mediated reactions occurred as part of the As(V) removal process. Raman spectroscopy studies confirmed that, in addition to surface reactions, internal interactions between the slag and arsenic also occurred. The findings of the study suggest that recycled Ni smelter slag could be an effective low-cost reactive medium for a subsurface remediation system, such as a permeable reactive barrier. Recycling of waste material (slag) for the removal of another waste (arsenic) can significantly reduce the environmental footprint of metallurgical operations and hence contribute to sustainable development. Such recycling also decreases slag disposal costs and eliminates the need to purchase commercial reactive material or obtain expensive natural material for remediation purposes.
在这项研究中，回收的镍冶炼炉渣被用作从水溶液中去除砷（As）的反应介质。研究结果表明，至少运行 65 天的、含有 451-550 克炉渣的 10.16-11.43 厘米长的柱子能够从初始砷浓度为 10 毫克/升的连续流动受污染水中去除 99-100%的砷物种。去除能力被发现为 1.039 至 1.054 毫克 As/克炉渣。X 射线光电子能谱（XPS）和拉曼光谱数据还表明，静电吸引和砷物种与渣中混合氧化铁之间的氧化还原反应是从水溶液中去除砷的主要机制。XPS 数据的理论多重分析表明，在通过吸附去除砷的过程中，炉渣中的针铁矿含量从 22%增加到 60%，而磁铁矿的百分比从 50%减少到 40%。这些变化表明，作为 As(V)去除过程的一部分，发生了氧化还原介导的反应。拉曼光谱研究证实，除了表面反应之外，炉渣和砷之间还发生了内部相互作用。研究结果表明，回收的镍冶炼炉渣可以作为一种有效的低成本反应介质，用于地下修复系统，如渗透性反应屏障。废物（炉渣）的回收利用，用于去除另一种废物（砷），可以显著减少冶金作业的环境足迹，从而有助于可持续发展。这种回收还降低了炉渣处理成本，并消除了购买商业反应材料或获得昂贵天然材料进行修复的需要。
